The present invention relates to immunomodulating compounds, pharmaceutical compositions comprising said compounds, use of said compound as well as a method for treatment of medical conditions which benefit from immunomodulation, wherein said compounds are administered.
The immune system possesses the ability to control the homeostasis between the activation and inactivation of lymphocytes through various regulatory mechanisms during and after an immune response. Among these are mechanisms that specifically inhibit and/or turn off an immune response. Thus, when an antigen is presented by MHC molecules to the T-cell receptor, the T-cells become properly activated only in the presence of additional co-stimulatory signals. In the absence of accessory signals there is no lymphocyte activation and either a state of functional inactivation termed anergy or tolerance is induced, or the T-cell is specifically deleted by apoptosis.
One such co-stimulatory signal involves interaction of CD80 on specialised antigen-presenting cells with CD28 on T-cells, which has been demonstrated to be essential for full T-cell activation. (Lenschow et al. (1996) Annu. Rev. Immunol., 14, 233-258).
In U.S. Pat. No. 4,312,870 compound A is disclosed as one of several psychoactive compounds but without any biological data. Some related compounds are described by A. Carotti in Bioorganic and Medicinal Chemistry 6 (1998) 389-399, and from data related to these compounds it is obvious that the carboxylic acid substituent greatly diminishes biologic activity measured as affinity for the CNS benzodiazepine receptor. 
EP 0354693A1 (Boots) discloses immunomodulatory compounds of general structure B but does not include structures wherein R7 and/or R8 are COOH or contain a COOH group. 
Similarly EP 0354694A1 (Boots) discloses immunomodulatory compounds of general structure C but no structures wherein R6 and/or R7 are COOH or contain a COOH group are described. 
Also, WO9111448 (Boots) discloses immunomodulatory compounds of general structure D but here are no structures wherein R7 and/or R8 and R8xe2x80x2 are COOH or contain a COOH group. 
The present invention relates in a first aspect to a novel compound having the general formula (I) 
wherein X represents a bond or a group selected from substituted or unsubstituted C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94CH2 or C(O)xe2x80x94NHxe2x80x94 (amino acid residue);
Y represents NR4, O or S;
R1 represents H, halo, CF3, lower alkyl or lower alkoxy;
R2 and R4 represents independently H or lower alkyl; and
R3 represents H, halo, lower alkyl or lower alkoxy, wherein halo is F, Cl or Br;
wherein lower alkyl represents saturated or unsaturated, straight, branched or cyclic alkyl groups having 1-6 carbon atoms; and
wherein lower alkoxy represents saturated or unsaturated, straight, branched or cyclic alkoxy groups having 1-6 carbon atoms,
with the proviso that R2 is not H, when X is a bond and Y is NH and R3 is H,
or pharmaceutically acceptable salts thereof.
In one preferred embodiment of the invention the compound X is a bond and in another preferred embodiment Y is NH.
In further embodiments the compound is selected from the group comprising
{[3-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenylcarbamoyl]-methoxy}-acetic acid,
N-[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-succinamic acid,
4-[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenylcarbamoyl]-butyric acid,
{[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenylcarbamoyl]-methoxy}-acetic acid,
4-[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenylcarbamoyl]-2-phenyl-butyric acid,
N-[3-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-succinamic acid,
2-{[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenylcarbamoyl]-methyl}-benzoic acid,
2-Chloro-4-(3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(6,8-Dimethyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(8-Methoxy-6-methyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(6,8-Dimethoxy-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(7,9-Dimethoxy-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(6-Methyl-3-oxo-8-trifluoromethyl-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
4-(7,9-Dichloro-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-propionic acid,
[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-phenyl]-acetic acid,
4-(4-Methyl-3-oxo-3H-chromeno[4,3-c]pyrazol-2-yl)-benzoic acid,
4-(3-Oxo-3H-thiochromeno[4,3-c]pyrazol-2-yl)benzoic acid,
4-(5-Methyl-3-oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoic acid,
2-[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoylamino]-3-phenyl-propionic acid, and
2-[4-(3-Oxo-3,5-dihydro-pyrazolo[4,3-c]quinolin-2-yl)-benzoylamino]-2-acetic acid.
In yet another embodiment said compound is a CD80 antagonist, capable of inhibiting the interaction between CD80 and CD28.
The present invention relates in a second aspect to a compound as set forth above for use as a medicament.
In one preferred embodiment said compound is used as a medicament for treatment of medical conditions chosen from the group comprising rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis.
The present invention relates in a third aspect to a compound as set forth above for use as a prodrug, preferably in the form of an ester.
The present invention relates in a fourth aspect to a pharmaceutical composition comprising said compound as active ingredient in association with a pharmaceutically acceptable adjuvant, diluent or carrier.
In one prefered embodiment said pharmaceutical composition is used for treatment of medical conditions chosen from the group comprising rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis.
The present invention relates in a fifth aspect to the use of a compound having the general formula (I) 
wherein X represents a bond or a group selected from substituted or unsubstituted C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94CH2 or C(O)xe2x80x94NHxe2x80x94 (amino acid residue);
Y represents NR4, O or S;
R1 represents H, halo, CF3, lower alkyl or lower alkoxy;
R2 and R4 represents independently H or lower alkyl; and
R3 represents H, halo, lower alkyl or lower alkoxy,
wherein halo is F, Cl or Br;
wherein lower alkyl represents saturated or unsaturated, straight, branched or cyclic alkyl groups having 1-6 carbon atoms; and
wherein lower alkoxy represents saturated or unsaturated, straight, branched or cyclic alkoxy groups having 1-6 carbon atoms, or pharmaceutically acceptable salts thereof, for the manufacture of a medicament for treatment of medical conditions which benefit from immunomodulation.
In one embodiment said medical conditions are chosen from the group comprising rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis.
The present invention relates in a sixth aspect to a method for treatment of medical conditions which benefit from immunomodulation comprising administration of a therapeutically effective amount of a compound having the general formula (I) 
wherein X represents a bond or a group selected from substituted or unsubstituted C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94C1-3-alkyl, NHxe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94CH2 or C(O)xe2x80x94NHxe2x80x94 (amino acid residue);
Y represents NR4, O or S;
R1 represents H, halo, CF3, lower alkyl or lower alkoxy;
R2 and R4 represents independently H or lower alkyl; and
R3 represents H, halo, lower alkyl or lower alkoxy,
wherein halo is F, Cl or Br;
wherein lower alkyl represents saturated or unsaturated, straight, branched or cyclic alkyl groups having 1-6 carbon atoms; and
wherein lower alkoxy represents saturated or unsaturated, straight, branched or cyclic alkoxy groups having 1-6 carbon atoms, or pharmaceutically acceptable salts thereof.
In one embodiment said medical conditions are chosen from the group comprising rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis.
In another embodiment said therapeutically effective amount per day is within the range of 0.001-10 mg/kg body weight, preferably within the range of 0.1-5 mg/kg body weight.
The present invention relates to heterocyclic compounds, to pharmaceutical compositions comprising them, and to methods and use of said compounds for clinical treatment of medical conditions which may benefit from immunomodulation, e.g. rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis. More particularly the present invention relates to heterocyclic compounds, which are CD80 antagonists capable of inhibiting the interactions between CD80 and CD28.
According to the present invention it has been found that compounds of general formula I are CD80 antagonists. Compounds of the general formula I inhibit the interaction between CD80 and CD28. The CD80 antagonistic properties of the compounds of general formula I have been established in Surface Plasmon Resonance (BIAcore) experiments.
It is preferred that X in the general formula I is a bond and in such cases other substituents, such as an adjacent meta-chloro, improves activity.
The compounds of the present invention may be in the acid form but may also be in the form of pharmaceutically acceptable salts.
The compounds of the present invention may also be in the form of prodrugs, especially esters with appropriate alcohols. Prodrugs can have improved pharmacokinetic and/or solubility properties.
Since the compounds of formula I are CD80 antagonists capable of interfering with the CD80-CD28 interaction they are useful for treatment of inflammatory conditions and autoimmune diseases, e.g. rheumatoid arthritis, multiple sclerosis, diabetes, asthma, transplantation, systemic lupus erythematosis and psoriasis.
Effective quantities of the compounds of formula I are preferably administered to a patient in need of such treatment according to usual routes of administration and formulated in usual pharmaceutical compositions comprising an effective amount of the active ingredient and a suitable pharmaceutically acceptable carrier. Such compositions may take a variety of forms, e.g. solutions, suspensions, emulsions, tablets, capsules and powders prepared for oral administration, sterile solutions for parenteral administration, suppositories for rectal administration or suitable topical formulations. Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described, for example, in xe2x80x9cPharmaceuticalsxe2x80x94The Science of Dosage Form Designxe2x80x9d, M. B. Aulton, Churchill Livingstone, 1988.
A suitable daily dose for use in the treatment of any of the conditions mentioned above is within the range of 0.001 mg/kg to 10 mg/kg body weight, in particular within the range of 0.01 mg/kg to 5 mg/kg body weight, depending upon the specific condition to be treated, the age and weight of the specific patient, and the specific patient""s response to the medication. The exact individual dosage, as well as the daily dosage, will be determined according to standard medical principles under the direction of a physician.
Various additives to enhance the stability or ease the administration of the drug can be added to the formulation. The pharmaceutical composition may also contain additional therapeutically useful substances other than one or more compounds of the general formula I.
The present invention is further illustrated by the following non-limiting experimental part.
Experimental Part
The compounds of general formula I may be prepared by the methods described below. The prior art patent documents cited above also include useful synthetic methods.
Thus, compounds of general formula I wherein Y=N and X is an alkyl chain can be prepared as shown in the reaction below; 
The starting material is available by known procedures (e.g. L. Savini et al, Bioorganic and Medicinal Chemistry 6 (1998) 389-399) and the reaction with hydrazine derivatives is performed by heating in a suitable solvent such as n-butanol. In cases where the acid is esterified under the reaction conditions, hydrolysis gives back the acid. Preparation of hydrazine derivatives was accomplished following literature procedures (Hunsberger et al, J. Org. Chem. 21 (1956) 394, 395, 396. Harden F. A. et al, J. Med. Chem. 34 (1991) 2892-8).
Compounds wherein R4 is lower alkyl may be obtained by subsequent alkylation. If the alkylation results in ester formation, the corresponding acid is easily obtained by hydrolysis. 
The compounds of general formula I wherein Y=O and X is an alkyl chain can be prepared according to various literature procedures (e.g. Ghosh C. K. Et al, Synthesis (1978) 779-781; Frogett J. A. et al, J. Chem. Research (S) (1997) 30-31). One synthetic route, when R2=Me, is described below. The cyano group is subsequently hydrolysed to produce the corresponding acid. 
The compounds of general formula I wherein Y=S and X is an alkyl chain can be prepared as shown below using procedures described in the literature (Donelly M. X. D. et al, J. Chem. Soc. Perkin Trans. 1 (1993) 1729-1735; Lombardino J. G. et al, J. Med. Chem. 24 (1981) 830-834). The final oxidation was accomplished by stirring in air. 
The compounds wherein X is a bond may also be obtained from the corresponding cyanide derivatives and the amino acid derivatives are prepared by condensation of the acid with the appropriate amino acid. 
Compounds wherein X is NHxe2x80x94C(O)-(alkyl)- and NHxe2x80x94C(O)xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94 can be prepared by reduction of the nitro group (L. Savini et al, Bioorganic and Medicinal Chemistry 6 (1998) 389-399) and subsequent acylation with the appropriate anhydride. 